Phonograph needle



Patented ct. 26, i948 UNETED STATES `ATNT OFFICE PHONOGRAPH NEEDJWilliam H. Hutter, Wheaton, Ill.

Application August 19, 1947, Serial No. '769,476

' 's claims (ol. zwi- 38) 1 This invention relates to improvements inphonograph needles.

It is an object of this invention to lprovide a phonograph needle ofsuperior fidelity of tone reproduction. One criterion of fidelity oftone re production is the wave shape of the signal voltage as observedon an oscillograph. If a needle is played on a frequency record in whichthe groove is modulated in the form of a sine curve, any departure ofthe wave shape from a sine curve indicates a corresponding lack ofdelity at that particular frequency.

This distortion of the wave shape is considered to be attributable tovarious causes. For instance, a given needle may have insufficientcompliance to enable it to follow the record groove. `Another cause ofdistortion appears to be the resonance of the tone arm, and otheracousticalresonances, such as crystal resonance-or system resonance.

Another criterion of fidelity of tone reproduction is the absence in thelfrequency response curve of peaks that are attributable to acousticcharacteristics of the needle. These peaks indicate the presence of anincreased signal strength at certain frequencies, which-is anundesirable f factor in musical reproduction. and are considered yto beattributable to resonance.

A further object of my invention is to provide a phonograph needlehaving the proper compliance in combination with sufficient mechanicalstrength to enable it to be subjected to the usage which is oftenencountered in record changers, in which the needle and Vtone arm aredropped through a distance of one to several inches on successiverecords. f

Another object of this invention-is to provide a needle which isrelatively free from needle scratch. The term needle scratch refers tothe extraneous noise transmitted through the needle, the pickup, theamplifier and the speaker, and is considered as being due to thepresence of hard particles or other surface irregularities inthe recordwhich impart an irregular movement to the needle over that imparted tothe needle by the groove. Although these. irregular movements are ofmuchsmaller magnitude than the motion of the needle which is caused bythe modulation of the groove in sound passages-of-,medium volume andmedium frequency, the ratio of noise to signal increases considerably inpassages of less volume and of higher frequency. Under such conditions,the needle scratch is more readily observed audibly but at all times itis considered to be objectionable.

A furtherobject is Vto provide a needle which is relatively free fromneedle talk. The term needle talk refers to the sound produced by theneedle in the air directly, due to its vibration. This sound issometimes the musical sound pro'- duced by the needle point followingthe modulations of the groove but at other times it is a noise which canbe attributable to a chattering of the needle due to its inability tofollow the groove or due to the presence of tone arm resonance or systemresonance. y,

I have found that the above objects canA be attained by fabricating theneedle, either in its entirety, or in part, from certain organic plasticmaterials, such as a certain type of nylon.

Fig. l is'an elevation showing one embodiment of my invention;

Fig. 2 is a elevation showing a modified form of the needle shown inFig. 1;

` Fig. 3 is an elevation showing another embodiment of my invention;

Fig. 4 is a view taken along line 4-4 of Fig. 3;

Fig. 5 is an elevation showing a modified form of the needle shown inFig. 3;

Fig. 6 is an enlarged elevation, partially in section, of a portion ofthe needle shown in Fig. 5;

Fig. 7 is an elevation of still another embodiment of my invention;

Fig. 8 is an elevation of a modified form of the needle shown in Fig. 7;

Fig. 9 is a sectional view taken along line 9 9 of Fig. 8; and

Fig. 10 is an elevation of a still further embodiment of my invention.

With reference now to the drawings, Fig. 1 shows a straight phonographneedle comprising a chuck engaging'portion I3, a stylus portion I2, anda connecting portion I3a which connects the stylus portion andv thechuck engaging portion. The portions I3 and 13a are both formed fromnylon and are integral with each other, and together comprise anelongate body member designated generally by the reference numeral I I.The stylus portion I2 is in the formof a separate stylus meml.ber andprojects from the lower end of the connecting portion I3a, to which itis suitably secured. The chuck engaging portion 4I3 is adaptn ed to bereceived within the usual chuck of a phonograph pick-up.

The stylus portion I2 may be formed of sapphire, or of a suitable metalor metal alloy, so as to provide a hard, long wearing stylus capable ofplaying several thousand records. The stylus is in the form of acylinder terminating-in a conical portion, the apex. of which may besomewhat rounded, the rounded apex having a radius from needle of Fig. 2is good for only a few plays, butv may be manufactured at considerablyless cost than the needle of Fig. l. The upperportion l of the bodymember I4 is adapted to be received within the usual chuck of a pickup.The lower portion serves to connect the' chuck engagingpor-1 tion |6 andthe stylus portion |5 and constitutes a connecting portion i3d. In orderto 'achieve better Wearing qualitiesof the stylus l5, it is considered4preerableto- -form the needle rfrom a nylon' whichjincludesasuitabiefiller, such asfaluminum powder.

Figs. 3- and-'24 illustrate'ia further embodiment of this invention.IThe needle-shown therein comprisesiai nylonbo'riy member |"|"ha', vinga metal shank |8i Them'etal shankl comprises aportion' {Uwhich isadapted to be' receivedw-ithin-the "usualiplokup chuck, arrdiaportion'of reduced diameter which is embedded in the upper portiorrv 2 'ofi thenylon body* member 1. Tli'e'- nylon bofdy member |1 is' preferablyinjection molded, and;the'sliank` lltakes the 'form of an insert, thenylonV being molded around the portion 20 and the 'lower 'extremity ofportions' Ig. The portion 23 may be knurled, as indicatedA in; thedrawings; or'der to providearmor'eisecure association ofthe parts. y

That portion of tl'ienylon body-` member' I1 which is below the endof'thepoition of the metal shankK isfa'll"A nylon', 'and 'can' bereferredy to as thenylonA connecting' portion 22. The: porfrom the undersurfacetlier-e'of. It'will be* ob- -servedf that this-'needle ifsaeharocterizedi by albend,

indicated generally by reference numeral 2W, the

'bendi being formed'in the nylonl connecting-L pornon 22. v

The portionlofoi" the metalli sliazil'r IIB- may be `slabbed asindicatedI by the reference; numeral 25 in`| order tofp'rovideI properorientationof the needle when the1 slabbe'd" portionV |91 is engaged byfthe set' screw oftliefpickup chuck'. lIt Will be observed thatthe'nylo'n body member |1 through- 'outth'e greaterfportion oi`- itslength istapered fbothl in-thicknessand` Width. The cross section oftheupper portion '2| oifthenylonlbody member isfgenerally circular anditmerges intothe rectangular cross sectionoi the nylonconnecting portion212;

"Inthe embodiment show-n in Figs- 5 and 6,

instead of being'v provided with agradual bend,

as in Figs. 3 and 4, the nylon bodymemb'er 26 visf'provided' with amabrupt bend designated generally' by thereference numeral-341 The needleofFigs. and 6 isf-provldedwith ametal `shank 27? which is similartoi-"the metalsha'nk l'Y o'f Figs. 3 ande'. The metal'shank I8 comprisesa slabbedg'portfion '28' adapted to 1 be' received'-V within tlieusuarlEpick-'upv chuck; and" affknurled portion noefsoi 29 of reduced diameterwhich is embedded With-- in the upper portion 30 of the nylon bodymember 26. The remainder of the nylon body member may be identiiiedgenerally as the nylon connecting portion 3|', but the abrupt bend 34divides the nylon connecting portion 3| into a. substantially verticallydisposed part 32 and a substantially horizontally disposed part 33. Theupper portion 3|! is of generally circular cross section; thehorizontally disposedl part 33 is of generally rectangular crosssection; and the circular cross section of one merges into therectangular cross section of the other in the vertically disposed part32. The nylon connecting portion 3| is tapered both in length and width.The abrupt bend 34 serves to increase the flexural vcompliance of theynylon connecting portion 3| in a vertical plane.

Asshown in Fig. 6, the substantially horizontally disposed part 33 isprovided with a bore 31 which partially intersects' the Dupper surface.of

the horizontally disposed member 33lftoprovide ari aperture` Sit-oi'smaller diameter' thanw the bore. A record'- engaging stylussissecur'ed in the bore 3-1 by' a suitable: cement 42u?, andthedimensions ofthe bore and of" the stylus;- aridi the mahnerofassociating the twose'cureim are substantially the same as pointedoutfin connectionlwith'v my copending application Seriall NmV 696,701,led Sep'- tember 133, 1946. In general; the-bore is of some'- whatsmaller diameter` than the diameter (of the cylindrical portion ofthestylus- 39'.v 'l'he cylir1d`1ic':a`.ly portion is'f' forced 1 intothe bore; and the resilience and' toughness or the nylon',`assistedfby-tire 'cement 4o,- cause the cylindrical portion to be*gripped very firmly.. 'The nylon body member 26 is preferably'injection molded aroundv the metalV 'shank y2?.

The needleshown'- in: ligi'fi comprises a... nylon body ll and al metalshank il?.V V"llfhe" nylonibody member 4| comprises an. upper portion.432 in Whichfav reduce'd -khurledportion'- 'ot the' shank i2`is-embedded, ando nylon.- connecting portion 4'4' which' issubstantiallynorizontauy disposed, and wniehrapproximates' in: dimensions andsnape,the dimensions. arid shape. ofthe horizo'r'ital`v part 33 of theneedleiof1igs.-.51anc` Astylusi isisecured in: theforwardi end` ofl thenylon: connecting portion 445 inmuclr the same'- manner' as pointed koutin` connection with'- the .needles of Figs. 5 and '6.

Figs. 8' andi` @illustratorl a needle'. somewhat simi'- lart'otheneedle-oi Fig. 'hinsofar as 'dimensions and operatingcharacteristics 'are concerned.

This needle comprises a nylon/body member,

andi al. metal shank 111.y the lower :reduced roortionl oi which-l'sern-be'ddedl in the' upper portion 4'8 of a nylon' body 'member $6.The nylon connecting.' portion 1491 -whioh1 isl subjected to'A theiiex'u'ral"and'- torsional vibrations caused Vby Ythe engagement of the`needle stylus 5|lwith 'the record groove, i'slof l'ess thickness thanthenylon connecting' portion l'M1 ci Fig'. '7l

The needle of-1 Fig. 1f0'1is similar to' the'rieed-le of Figsjand 6`,with3 the.v exception: that instead of the' metalisha-rik 212,V theupperportion'or chuck engaging'portion 52T or theneedle' isforrnedlfromnylon, and is integrarwithA the remainder ofthe needle. The nylon `bodymember is designated generally byt-he reference' numeral'- 5|andincludes, i'n addition to the chuck engaging' portion 5'2,elifsubstantia-lly vertically' disposed part 53"', andasubstantially'horizontally disposed; part 54. A stylus 55 is insertedtoward the forward or outer'en'd ollpa-rty l'5|-iii-thesamemanner as4'pointed 'out in connection with the preceding A taken of the -factthat the kdrawings "(except for Fig'. 6) are scaled to fabouthfour times-the 'actual size. For instance, the needle of Fig. l is about 5/8 .ofan inch long and .070 inch fin diameter.

4It will be apparent that lthe desirable characteristics which flow fromthe use 'of nylon in a phonograph needle are obtained when at least aportion of the nylon body member comprises a connecting portion: thatis, a compliant unstiiened portion which can be subjected to flexural orflexural and torsional strains. The length ratio of the nylon connectingportion to the needle as a whole can vary anywhere from about one toeight up to unity. For instance, in Fig. 7 the length of the centroidalaxis of the needle as a whole is designated by the reference characterA, and is approximately 3/4 of an inch; whereas, the length of thecentroidal axis of just the homogeneous portion is design-ated by thereference character B, and is approximately 1/i of an inch. Thus thelength ratio is approximately one to six.

The corresponding dimension B in the needle of Fig. 8 is approximately35 of an inch, so that the length ratio of that needle is approximatelyone to eight.

The nylon connecting portion of each needle shown in the drawings iselongate; that is, its length is greater than either its average widthor average thickness. However, where vertical compliance is primarilydesired the width could equal or exceed the length, and where horizontalcompliance is primarily desired, the thickness could equal or exceed thelength. The exact proportions of length to thickness or of length towidth, and the degree of taper, if any, may be varied according to thecharacteristics desired.

The nylon body members of the needles shown in the drawings may beformed from these types of nylon designated as FMlOOOl nylon and FM3001nylon (formerly designated as FlVll nylon and FB/I3 nylon,respectively). These types of nylon, as far as I know, are manufacturedand sold only by the E. I. du Pont de Neumours and Company, ofArlington, New Jersey. I prefer to use FM10001 nylon, which in itsnatural unlled and unpigmented state is a translucent white in color.However, the needle of Fig. 2, as pointed out above, preferably embodiesan aluminum ller, and the needle of Fig. 10 is preferably formed from ablack FM10001 nylon.

The metal Shanks, where used, are preferably of aluminum alloy.

The word nylon as used herein, refers to a substance sold by E. I. duPont De Nemours dz Co. which is defined by them as a generic term forany long-chain synthetic polymeric amide which has recurring amidegroups as an integral part of the main polymer chain, and which iscapable of being formed into a filament in which the structural elementsare oriented in the direction of the axis. Nylon may otherwise bedefined as a fiber-forming polymer including synthetic linearcondensation polyamides formed by reacting organic diamines with dibasicacids or with the amide-forming derivatives of dibasic acids, andpolyamides formed from polymerizable amino acids.

The organic plastic material of which the body membersv of the needlesherein disclosed are formed may also be identified by 'certain physicalcharacteristics set forth below. FM10001 nylon and FM3001 nylon havethose physical characteristics. As used herein, the term nylon havingsubstantiallythe same physical characteristics as FM10001 nylondesignates nylon, including .FMlOOOl nylon, having physicalcharacteristics which fall within the ranges set forth in the followingtabulation.

Test Characteristic irggfl. Values Designation Specific gravity 1.09 to1.16.`

low temperature D560-43 Not less than 400 F. Deformation under load.D62143 Nclizoniore than 5% at Stilness in flexure D747-43T... 150,000 to300,000 pounds per square inch at 77 F. Flexural strength D650-42T 8,000to 15,000 pounds per square inch at 77 F. Heat distortion temper-D648-44T Not less than from 130 F. ature. to 171 F. for l0 milsdeflection at 264 pounds per square inch M50 to M Rockwell. HardnessD-22943 $4" ball; minor load l0 kilograms; major load 100 kilograms.

FM10001 and FM3001 are made in accordance with the disclosure of UnitedStates Patent No. 2,130,948, issued September 20, 1938, to Wallace HumeCarothers.

The use of the iiller or pigments in combination with an organic plasticmaterial having physical characteristics falling within the ranges setforth in the above tabulation shall be included in the term havingphysical characteristics essentially the same as FM10001 nylon eventhough the use of such llers or pigments would increase the specificgravity beyond the range specified.

This application is a continuation in part of my copending applicationSerial No. 590,329, filed April 26, 1945, and the subject matterthereof, insofar as it is consistent with this application, is herebyincorporated by reference into this application.

I claim:

1. A phonograph needle comprising a stylus portion, a chuck engagingportion, and a portion connecting said stylus portion and said chuckengaging portion, said connecting portion being formed from nylon havingsubstantially the same physical characteristics as FM10001 nylon andbeing of a length of at least one eighth of the total length of theneedle.

2. A phonograph needle according to claim 1, in which said stylusportion comprises a separate stylus member inserted in said connectingp0rtion at substantially an end thereof.

3. A phonograph needle according to claim 1, in which a part of saidconnecting portion is disposed at an angle with respect to said chuckengaging portion such that when said chuck engaging portion is grippedwithin the chuck of a pickup cartridge, the axis of said part will bedisposed substantially parallel to the plane of a phonograph record whenthe needle is in cooperative relation thereto, and in which said stylusportion comprises a separate stylus member projecting from a face ofsaid part.

4. A phonograph needle according to claim 1, in which said chuckengaging portion comprises a metallic member, a part of which isembedded in said connecting portion.

5. A phonograph needle comprising a stylus portion, a vchuck engagingportion, and a portion A phonograph needle comprising a kstylusV-porton, a chuck engaging fp'ortion, and a. .por-tion coz-meeting saidstylus portion and `said .chuck-en- 'igaging portion, said `connectingfportion Lbeing formed from FMBUGI nylon and being fof afl'ength nof `atieastone eighth `of the total `length of the needle.

7. A phonograph needlezcomprising-,a-body portion formed from FMIOOOInylon, a metallic `vchuck engaging portion having Aa portion embedded insaid -nylon body portion, and ,va-'stylusnsented in s'a'id nylon body-portionat .substantially the end thereof `remote from .said metallicchuck ien portion, isa-in fnylon ibody portion "being of a length of atleast one eighth of the total flengthaof the fneed'le `and serving toConnect :said

vNo references oited.

